Trailing 3-1 to a qualifier on the first day of Wimbledon, the top-ranked player was not about to drop the opening set as she did four times during her run to the French Open title.

“She came out so fast, I was like, `Oh my God, if I don't start I'm going to be down a set.’ And I was tired of being down a set,” Williams said.

So the five-time champion got to work, winning 11 of 13 games to beat 113th-ranked Margarita Gasparyan of Russia, 6-4, 6-1, on Monday to extend her Grand Slam winning streak to 22 matches as she pursues a fourth straight major title.

Things were more straightforward for defending men's champion Novak Djokovic, who opened play on Centre Court and led all the way for a 6-4, 6-4, 6-4 win over Philipp Kohlschreiber of Germany.

“It's great to be back,” said Djokovic, who beat Roger Federer in last year's final. “This is the cradle of our sport, Centre Court. It doesn't get any better than Wimbledon.”

As rightfully proud as the All England Lawn Tennis and Croquet Club is of its manicured...

When Bob and Mike Bryan take the court for one of their doubles matches at Wimbledon this week, they might smile and tell each other they have played on better grass courts than this at home.

Because they have.

As rightfully proud as the All England Lawn Tennis and Croquet Club is of its manicured...

(Bill Dwyre)

Williams, who played the opening match on Court 1, is seeking to become the first player since Steffi Graf in 1988 to complete a calendar-year Grand Slam, a sweep of all four major titles in the same season.

Not only did Williams get off to another slow start Monday, she also got a warning for her language. In the sixth game, she received a code violation for an audible obscenity after sliding on the grass and falling during a point.

But Williams was able to impose herself on an opponent making her Wimbledon debut.

“I knew she would be a good player,” Williams said. “I can't say I thought she'd be that good, to be honest.”

Photos from the 2015 Wimbledon Championships at the All England Lawn Tennis and Croquet Club in London.

Also reaching the second round was Serena's sister, Venus, also a five-time champion at Wimbledon. The 16th-seeded Venus recorded a double-bagel, beating Madison Brengle 6-0, 6-0 in just over 40 minutes.

Venus, who could face Serena in the fourth round, had 29 winners, compared to just two for Brengle.

Kohlschreiber, the highest-ranked men's player outside the seedings at No. 33, had figured to pose a stiff test for Djokovic, who came to Wimbledon after a painful loss to Stan Warwinka in the French Open final and without having played a warm-up tournament on grass.

But the Serb was rarely troubled, seizing command with his all-court game, serving 12 aces and breaking five times.

Djokovic displayed frustration in the post-match news conference when he was asked for a second straight day about comments by his coach, Boris Becker, that they have ways of communicating with each other during matches.

Coaching during a match is against the rules, but Djokovic said that is not what is going on.

“There are certain ways of communication which is encouragement, which is support, which is understanding the moment when to clap or say something that can lift my energy up, that can kind of motivate me to play a certain point,” Djokovic added. “But it's all within the rules.”

Djokovic was followed on Centre Court by Maria Sharapova, who won Wimbledon title at 17 in 2004. The fourth-seeded Russian also had a trouble-free opener, sweeping to a 6-2, 6-2 win over Britain's Johanna Konta.

One former champion, however, bowed out on Day 1.

Making his 17th and final Wimbledon appearance, 2002 winner Lleyton Hewitt saved three match points before falling in five sets to Finland's Jarkko Nieminen, 3-6, 6-3, 4-6, 6-0, 11-9, in a four-hour battle on Court 2.

The 34-year-old Hewitt has said he will retire after next year's Australian Open. After a warm embrace with Nieminen at the net, Hewitt went back onto the court without his racket to acknowledge the loud ovation and wave to the fans.

Wawrinka also played on Centre Court, and the fourth-seeded Swiss looked sharp on the grass as he beat Joao Sousa of Portugal, 6-2, 7-5, 7-5 (3). Wawrinka could face Djokovic in the semifinals.